The invention relates to a method for applying at least one electric field to adherent cells, in which the electric field is generated by applying a voltage to at least two active electrodes, wherein at least three electrodes are provided. The invention further relates to a device comprising at least three electrodes which are connected to at least one voltage source via at least one switching device. The invention also relates to a device for contacting at least two electrode arrangements which each comprise at least two electrodes, wherein at least two electrode arrangements have different dimensions and wherein the device includes contact elements by means of which an electrical contact can be made to the electrodes of the electrode arrangements.